226 Merrill Science
PO Box: AC# 2244
Assistant Professor of Astronomy
Departmental affiliation: Physics and AstronomyAmherst College
Professional and Biographical Information
Ph.D., Astronomy, University of Washington (Seattle, WA), August 2010
M.Sc., Astronomy, University of Washington (Seattle, WA), December 2006
M.Sc., Physics, San Francisco State University (San Francisco, CA), June 2004
B.A., Philosophy & Mathematics with Honors, St. John's College (Santa Fe, NM), May 1995
My goals as a new faculty member at Amherst College are three-fold: (1) to inspire non-majors, majors, and the public with the depth, richness, and excitement of astrophysics, (2) to lead cutting-edge research on accretion-driven inflow and outflow onto compact objects (black holes, neutron stars, and white dwarfs), (3) to cultivate effective and insightful scientists who regard diversity as a core value.
I am an observational astronomer — my research explores the interplay between growing supermassive black holes (SMBHs), a.k.a. active galactic nuclei (AGN), and their host galaxies. Rapid growth of SMBHs occurs when gas and dust flow to the innermost regions of a galaxy, spiraling into a hot, bright accretion disk, and falling across the event horizon (hence disappearing from view). Inflowing gas is also responsible for star formation in the galactic bulge. The bulge and the central black hole may even be connected via physical process that are not well understood, a connection across nine orders of magnitude! One candidate is feedback, wherein jets and winds from the accretion disk regulate both the growth of the central black hole (at small scales) and star formation (at much larger ones). During growth cycles, AGN are highly variable, since the accretion disk, jets, and winds are all dynamic structures.
My research involves strategic surveys of AGN at multiple wavelengths (X-ray, optical, IR, and radio) and on a wide range of time scales (days, months, and years). My most recent work, highlighted on my webpage, has focused on the Galactic Center and Sgr A*.
If you are interested in conducting undergraduate research with me please send me an email. I am always looking for good students, especially freshman!
1. Rea, N., et al., "A Strongly Magnetized Pulsar within Grasp of the Milky Way’s Supermassive Black Hole", 2013, Astrophysical Journal Letters, 2013, 775, 34
2. Neilsen, J., Nowak, M., Gammie, C., Dexter, J., Markoff, S., Haggard, D., et al., "A Chandra/HETG Census of X-ray Variability from Sgr A* During 2012", 2013, Astrophysical Journal, 774, 42
3. Wang, Q.D., et al., "Dissecting the X-ray-emitting Gas Around Sgr A*", 2013, Science, 341, 981
4. Haggard, D., Cool, A.M., Heinke, C.O., Cohn, H.N., Lugger, P.M., van der Marel, R., Anderson, J., A "Deep Chandra X-ray Limit on the Putative IMBH in Omega Centauri", 2013, Astrophysical Journal Letters, 773, L31
5. Cool, A.M., Haggard, D., et al., "HST/ACS Imaging of Omega Centauri: Optical Counterparts of Chandra X-Ray Sources", 2013, Astrophysical Journal, 763, 126
6. Haggard, D., Green, P.J., Anderson, S.F., Constantin, A., Aldcroft, T., Kim, D.- W., "The Field X-ray AGN Fraction to z=0.7 from the Chandra Multiwavelength Project and the Sloan Digital Sky Survey", 2010, Astrophysical Journal, 723, 1447
7. Haggard, D., Cool, A.M., & Davies, M.B., "A Chandra Study of the Galactic Globular Cluster Omega Centauri", 2009, Astrophysical Journal, 697, 224
8. Haggard, D., et al., "HST Advanced Camera for Surveys Imaging of ω Centauri: Optical Counterpart for the Quiescent Low-Mass X-Ray Binary", 2004, Astrophysical Journal, 613, 512